Skip to main content

Quiet hours

Quiet hours silence a phone number or email address during a window you choose — overnight, during meetings, or whenever an alert would do more harm than good.

The window is set per channel, not per account, so you can silence your phone overnight while a shared team inbox keeps receiving everything.

What quiet hours affect​

Quiet hours apply to SMS and email channels only. Slack always delivers, because a Slack message waits quietly until someone reads it — it doesn't wake anyone.

Each channel carries its own timezone setting, so the window you enter is the local time you mean, wherever the recipient is.

Nothing is lost​

An alert that arrives during your quiet hours isn't discarded. When your window ends, we send one summary — "you missed 3 alerts during quiet hours" — with a link to a page listing each one. Individual alert links from that page stay accessible afterward.

Warnings that always deliver​

Some warnings are worthless if they arrive late. Each channel has an Override for critical warnings setting; turn it on and the warnings below break through the quiet-hours window and deliver immediately.

Everything else waits, and appears in your summary.

Storm hazards​

  • Tornado Warning — a tornado is occurring or imminent
  • Severe Thunderstorm Warning — damaging winds or large hail are occurring
  • Flash Flood Warning — flooding is occurring or imminent
  • Extreme Wind Warning — sustained winds of 115 mph or more are imminent

Evacuation and shelter orders​

  • Evacuation Immediate — leave the area now
  • Shelter In Place Warning — stay inside and seal the building

Hazardous releases​

  • Hazardous Materials Warning — a chemical release threatening the area
  • Radiological Hazard Warning — a radiological release threatening the area
  • Nuclear Power Plant Warning — an incident at a nuclear facility

Geophysical hazards​

  • Tsunami Warning — a tsunami is expected; move inland and to high ground
  • Earthquake Warning — shaking is imminent
  • Volcano Warning — a hazardous eruption is occurring or imminent
  • Avalanche Warning — imminent avalanche danger in the terrain named

Other immediate threats to life​

  • Fire Warning — a fire is threatening the area now
  • Civil Danger Warning — a threat to life with a protective action to take
  • Law Enforcement Warning — an active law enforcement danger to the public

What does not break quiet hours​

Hazards that give you hours or days of notice deliver normally during your waking hours and wait when you're silenced — including hurricane, typhoon, and tropical storm warnings, storm surge warnings, and extreme heat warnings.

This is deliberate, and it's what keeps the setting useful. A hurricane warning issued at 3am tells you exactly what it would tell you at 7am. Waking someone for it teaches them to switch the override off, which would cost them the warnings in the list above — the ones where minutes genuinely matter.

Ashfall warnings, snow squall warnings, dust storm warnings, and special marine warnings are excluded for the same reason: they're urgent for someone already driving or underway, not for someone asleep at home.

Turning it on​

Open Delivery Channels, expand a phone number or email address, and set your window under Quiet hours. The Override for critical warnings toggle sits directly beneath it.

The override is off by default. Turning it on for at least one channel is worth considering if anyone relying on that channel would need to act overnight.

  • SMS limits — a separate, larger list of warnings that send even after your monthly SMS quota is spent. A warning can bypass the quota without breaking quiet hours; the two settings answer different questions.
  • Priority — filter a channel down to high-priority rules only.